DESCRIPTION (Applicant's Description-edited) The recent identification of mutations in breast cancer susceptibility genes has provided the exciting opportunity to help identify women who are at high risk to develop breast cancer. One of the serious impediments to achieving the clinical benefits from this information is due to the difficulty in finding and assessing the significance of mutations in these new susceptibility genes. It is imperative that the detection and interpretation of these mutations is coordinated and this information is made available to as many qualified investigators as possible. We consider it important to create and maintain a central repository for information regarding mutations and polymorphisms. We also think it critical to make available the information, both protocols and primers, necessary to carry out many different techniques for detection of such mutations. When the BRCA1 gene was cloned last October, a Steering Committee was initiated to help coordinate the formation of a Breast Cancer Information Core (BIC) that could act as such a central repository. We have chosen the most accessible format for the BIC, an FTP site on the Web which would be accessible by a password provided to members who abide by a set of Guidelines. The funds requested are to help set up and maintain this FTP site that will provide a central repository for the information mentioned above. Such access to information should allow many investigators to have common tools by which to analyze genes such as BRCA1, BRCA2, and AT as they are identified. This access will greatly enhance the ability to help identify and interpret the importance of this genetic information.